贫电子环丙烷衍生物与胂叶立德的反应研究

The reaction of electron-deficient cyclopropane derivatives, cis-1-methoxycarbonyl-2-aryl-6,6-dimethyl-5,7dioxospiro[2,5]octa-4,8-diones with benzoylmethylenetriphenylarsorane (2) and methoxycarbonylmethylenetriphenylarsorane (4) was found to form cis,trans-l-methoxycarbonyl-2-aryl-3-benzoyl-7,7-dimethyl-6,8-dioxospiro[3,5]nona-5,9-dione (3a-3e) and trans,cis,trans-5-[2‘-methoxycarbonyl-2‘-(triphenylarsoranylidene)acetyl]-6oxo-3-aryl-tetrahydro-pyran-2,4-dicarboxylic acid dimethyl esters (5a-5c) respectively with high stereoselectivity. The possible reaction mechanisms for the formation of the different products were also orooosed.     

X-H (X = C, N, O, Si, P, S) 键离解能计算的密度泛函方法研究

使用了不同密度泛函方法计算X-H (X = C, N, O, Si, P, S) 键离解能，并分析不同密度泛函方法的计算精度。研究发现大多数密度泛函方法包括B3LYP, B3P86, B3PW91, G96LYP, PBE1PBE，和BH&HLYP都明显低估键离解能13-25 kJ/mol。该现象与是否使用无限基组无关，因为即使使用无限基组键离解能仍然被低估。因此密度泛函方法不适合用于键离解能的估算。其中B3P86方法的偏差最小。进一步分析表明，使用限制性开壳层计算并无任何优势，在大多数情况下非限制性开壳层计算实际上比限制性开壳层计算要好。最后，我们发现了密度泛函方法对键离解能的低估是系统的，因此建议利用校准后的UDFT/6-311++G(d, p)方法计算化学键离解能。     

SCATTERING FUNCTION OF POLYMER BLENDS

For a system of flexible polymer molecules, the concepts of two concentrations, namely the segmental and the molecular concentrations, have been proposed in this paper. The former is equivalent to the volume fraction. The latter can be defined as the number of the gravity centers of macromolecules in a unit volume. The two concentrations should be correlated with each other by the conformational function of the polymer chain and should be discussed in different thermodynamic equations. On the basis of these concepts it has been proved that the Flory-Huggins entropy of mixing should be the result of the mixing “ideal gases of the gravity centers of macromolecules“. The general correlation between the free energy of mixing and the scattering function (structural factor) of polymer blends has been studied based on the general fluctuation theory. When the Flory-Huggins free energy of mixing is adopted, the de Gennes scattering function of a polymer blend can be derived.     

Structure and Thermal Stability of a Novel 2‐D Layered Copper(II) Coordination Polymer with the Bidentate Ligand 1, 2, 4‐Triazol‐5‐one

Single crystals of {[Cu(TO)₂(H₂O)₂](NO₃)₂}_n (TO: 1, 2, 4‐triazol‐5‐one) were grown by slow evaporation from aqueous solution. It crystallizes in the orthorhombic space group Pbca, with a = 7.082(1), b = 10.285(1), c = 17.911(3)Å, V = 1304.6(3)ų, Z = 4. The Cu^II distorted octahedra are bridged by bidentate TO ligands into infinite 2‐D interlaced rhombic grid‐like network planes, {[Cu(TO)₂(H₂O)₂]²⁺}_n. Hydrogen bonds, electrostatic interactions, and weak van der Waals' forces assemble these planes and the NO₃^— anions to a layered structure. The title compound decomposes at 153.4 °C to the final products, Cu(CN)₂ and CuO.     

Molecular Simulation on Transport Properties of Confined Water

The diffusivity and viscosity of water confined in micropores were studied by molecular dynamics simulations. The effects of pore width and density were analyzed at pore widths from 0.9 to 2.6nm. The diffusivity in micropores is lower than that of the bulk, and it decreases as pore width decreases and as density increases. But the viscosity in micropores is much larger than that of the bulk, and it increases as pore width decreases and as density increases. The diffusivity in channel parallel direction is obviously larger than that in channel perpendicular directions.     

N—乙基—N—苄基苯胺合成方法的改进

以苯胺和乙醇为原料，采用ＲａｎｅｙＮｉ为催化剂，合成了Ｎ－乙基苯胺，再在相转移催化剂作用下，经苄基化反应得到标题化合物，第一步合成方法的收率比通常方法的收率提高约３０％。     

A dimer of α‐ and β‐dihydro­arte­misinin: bis­(3,6,9‐trimethyl‐3,12‐epidioxy‐3,4,5,5a,6,7,8,8a,9,10‐deca­hydro‐12H‐pyrano[4,3‐j][1,2]­benzo­dioxepin‐10‐yl) ether

The title compound, C₃₀H₄₆O₉, prepared from a mixture of α‐ and β‐dihydro­artemisinin, has α‐ and β‐arteether moieties linked via an –O– bridge, so that the mol­ecule is asymmetric about the bridge. The endoperoxide bridges of the parent compounds have been retained in each half of the ether‐bridged dimer. The rings exhibit chair and twist–boat conformations.     

碳纳米管为基质对氨基酸的MALDI-FT MS分析

Twenty common amino acids have been analyzed successfully by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) using carbon nanotubes as matrix. From the spectra, little or no background interference or fragmentation of the analytes has been observed. This method was also applied to the analysis of amino acid mixture successfully. Carbon nanotubes have some features such as large surface area to disperse the analyte molecules sufficiently and prevent the sample aggregation and strong ultraviolet absorption to transfer energy easily to the analyte molecules. The present method has potential application for the rapid and sensitive analysis of amino acids and their mixture.     

High accuracy mass measurement of peptides with internal calibration using a dual electrospray ionization sprayer system for protein identification

A dual-ESI-sprayer system was constructed and applied to achieve high accuracy of peptide mass measurement for protein identification by means of peptide mapping. Sample was introduced in one sprayer, and reference in the other, thus making internal calibration possible greatly enhancing the mass accuracy. Several samples were utilized to evaluate the reliability of this dual-ESI-sprayer system. The range of mass errors was 0.16-5.37 ppm. The peptide masses of tryptic digests of myoglobin (horse) were measured by the HPLC/dual-ESI-MS system, with mass deviations ranging from 0.01-7.67 ppm, and about 75% mass deviations below 5 ppm with 40% below 1[?]ppm. These peptide masses were utilized to perform database searching for protein identification, and compared to results obtained by external calibration. This comparison showed that the internal calibration provides a more reliable method of protein identification, with a much smaller number of required peptides for matching, and with less CPU time consumed for database searching.     

2,2’-二氨基苯氧基二硫化物的电极过程动力学研究

利用循环伏安法、线性伏安法及旋转圆盘电极技术，研究了2,2’-二氨基苯氧基二硫化物(DAPOD)在含有0.1 mol•L－1 LiClO4电解质的乙腈/四氢呋喃有机溶液中，铂、金、玻碳及石墨电极上的电化学行为.伏安结果表明DAPOD中的二硫键与硫巯基之间的氧化还原反应属动力学不可逆过程，这种在室温下表现出的电化学反应不可逆性是有机二硫化物普遍存在的不足，必须通过分子内或分子间的电催化来改善其可逆性能.旋转圆盘电极测试结果显示， DAPOD的阴极还原反应级数为0.5，阳极氧化反应级数为1.由此推知DAPOD电还原属两电子转移反应，分两步完成：第一步为平衡的化学反应步骤；第二步为电子转移步骤，属决速步.同时还测定了DAPOD的阴极与阳极传递系数、交换电流、平衡电势及标准速率常数等相关的动力学常数.通过比较铂、金、玻碳及石墨四种不同材料电极对DAPOD的电极过程的影响,发现石墨对DAPOD的还原过程具有电催化作用.